on the sly

US /ɑn ðə slaɪ/
UK /ɑn ðə slaɪ/
"on the sly" picture
1.

سراً, خلسة, على غفلة

doing something secretly or furtively

:
•
He was eating cookies on the sly when his mom wasn't looking.
كان يأكل البسكويت سراً عندما لم تكن والدته تنظر.
•
They were meeting on the sly to plan the surprise party.
كانوا يجتمعون سراً للتخطيط لحفلة المفاجأة.
:
sly